Interaction of SiH3 radicals with deuterated (hydrogenated) amorphous silicon surfaces

Interactions of SiH3 radicals with surfaces of deuterated amorphous silicon (a-Si:D) and hydrogenated amorphous silicon (a-Si:H) films were studied using attenuated total reflection Fourier transform infrared spectroscopy and molecular-dynamics simulations, respectively. SiH3 radicals abstract surface silicon deuterides through an Eley-Rideal abstraction reaction. Surface deuteride abstraction occurs on the same time scale as SiH3 insertion into Si-Si bonds over the substrate temperature range of 60-300 °C. Some fraction of SiH3 adsorbing on the a-Si:D/a-Si:H films dissociates and releases H into the subsurface. These observations are consistent with the temperature independent reaction probability of SiH3 and the temperature dependent smoothening mechanism of a-Si:H thin films.